The convergence of recent extreme-weather events and international conflicts has heightened concerns about the vulnerability of the global food system to shocks. Yet, it remains unclear what shocks most affect a country’s food supply, and what role trade and other food system characteristics play in mitigating or amplifying negative impacts. Here, using a newly developed global bilateral trade model representing 177 countries and four major staple crops (maize, wheat, rice, soybean), we simulate the food supply, trade and price impacts resulting from climate-related yield variability, and shocks motivated by (i) the Ukraine war, (ii) the recent energy price shock, (iii) observed trade bans, as well as (iv) a compound shock (i-iii together). The energy price shock has the greatest effect of the first three shocks, and dominates the effect of the compound shock across most regions and crops. We find that in many instances trade adjustments can help cope with both supply and price shocks, but that this is shaped by a combination of factors that characterize a country’s coping capacity. If the compound shock occurs at a time of poor global weather for agriculture, the total drop in consumer surplus that year can be over USD 600 billion and affect most countries simultaneously. The modelling approach developed here can be a useful tool to identify vulnerabilities in food systems and to develop targeted strategies to enhance resilience, such as strategic stockpiling, schemes to support domestic production or new trade agreements.

Despite the growing accessibility of international grain and oilseed markets, high production costs and trade frictions are still prevalent, contributing to regional heterogeneities in the landed cost of grain imports. Here we quantify the landed cost for six grain commodities across 3,500 administrative regions, capturing regional cost differences to produce grain and transport it across international borders. We find large heterogeneities in the costs of imported grain, which are highest in Oceania, Central America and landlocked Africa. While some regions have uniform landed costs across sourcing locations, others face cost variations across trading partners, showing large inequalities in access. We find that most regions could benefit from a targeted approach to reduce landed cost while others benefit from a mixed strategies approach. Our results highlight that spatial information on production, trade and transport is essential to inform policies aiming to build an efficient and resilient global agricultural commodity trade system.

Global trade relies on a small number of strategic passageways, so-called maritime chokepoints, which are vulnerable to disruptions. Yet, the exposure of countries to these disruptions has not been comprehensively assessed, inhibiting adequate preparedness. Here, we quantify the systemic impacts of maritime chokepoint disruptions subject to a variety of hazards, both natural and human-induced. The expected value of trade disrupted at chokepoints is estimated to be USD192 billion annually, mainly attributed to geopolitical risk at the Taiwan Strait and Suez Canal, and a combination of hazards affecting the Bab el-Mandeb Strait. We estimate the economic losses of chokepoint disruptions, due to delays, rerouting, insurance premiums and trade disruptions, to be USD10.7 billion per year, and an additional USD3.4 billion per year due to increased freight costs. In both cases, risks to the Suez Canal and Bab el-Mandeb Strait drive these losses. Countries most affected are in the vicinity of these two chokepoints, but also further away, including countries in Western Africa and Central Asia. At a time of heightened geopolitical tensions and climate change, our results help to quantify the implications of these risks and can present a useful starting point to identify resilience interventions to mitigate these threats.

Ports are exposed to multiple climate hazards, including windstorms, floods, and intense rainfall. These hazards often occur simultaneously, thereby amplifying their overall effects. Here, we develop a compound risk assessment that incorporates the probabilities of the joint occurrence of climate hazards and their compound effects on port infrastructure systems. We evaluated the direct infrastructure damages, revenue losses due to disruptions, and operational downtime. Furthermore, we analysed the temporal dependence of climate hazards across multiple ports to understand how compound events trigger economic impacts at the continental scale, tracing the dependency structure from hazards to impacts. This methodology was applied to the European port system, where the results show the importance of considering compound effects when evaluating climate risks. Consideration of compound effects on a continental scale adds up to €360 million in additional direct damages (35% of the annual average direct damages) and €10 million due to loss of service (6% of annual average losses). Moreover, failure to account for the interactions between co-occurring impacts results in an underestimation of €100 million in expected annual losses across European ports.

Green ammonia has been proposed as a technologically viable solution to decarbonise global shipping, yet there are conflicting ambitions for where global production, transport and fuelling infrastructure will be located. Here, we develop a spatial modelling framework to quantify the cost-optimal fuel supply to decarbonise shipping in 2050 using green ammonia. We find that the demand for green ammonia by 2050 could be three to four times the current (grey) ammonia production, requiring major new investments in infrastructure. Our model predicts a regionalisation of supply, entailing a few large supply clusters that will serve regional demand centres, with limited long-distance shipping of green ammonia fuel. In this cost-efficient model, practically all green ammonia production is predicted to lie within 40° latitudes North/South. To facilitate this transformation, investments worth USD 2 trillion would be needed, half of which will be required in low- and middle-income countries.

Many drinking water utilities face immense challenges in supplying sustainable, drought-resilient services to households. Here we propose a quantified framework to perform drought risk analysis on ~5600 potable water supply utilities and evaluate the benefit of adaptation actions. We identify global hotspots of present-day and mid-century drought risk under future scenarios of climate change and demand growth (namely, SSP1-2.6, SSP3-7.0, SSP5-8.5). We estimate the mean rate of unsustainable or disrupted utility supply at 15% (interquartile range, 0–26%) and project a global increase in risk of between 30–45% under future scenarios. Implementing the most cost-effective adaptation action identified per utility would mitigate additional future risk by 75–80%. However, implementing the subset of cost-effective options that generate sufficient tariff revenue to provide a benefit-cost ratio that is greater than 1 would only achieve 5–20% of this benefit. The results underline the challenge of attracting the financing required to close the climate adaptation gap for water supply utilities.

Climate-related disruptions to water supply infrastructure services incur direct financial losses to utilities (e.g. to repair damaged assets) and externalise a societal cost to domestic customers due to additional costs that they may incur (e.g. to acquire water from alternative sources). The latter often represents an uncompensated social burden, which should be properly accounted for in investment planning. Here we present a new framework for quantifying direct financial risks burdened by utilities and alternative water purchase losses incurred by domestic customers, including those in low-income groups, during flood- and drought-induced utility water supply disruptions. This framework enables the comparison of benefit-cost ratios of a portfolio of flood protection and leakage reduction for water supply systems across the island of Jamaica. A system-level optioneering analysis allows the identification of the optimal adaptation option per system. We estimate that 34% of systems would benefit from flood defences and 53% would benefit from leakage reduction to adaptation to droughts. The benefit that could be achieved by implementing all system optimised adaptation options is estimated to be 720 million Jamaican dollars per year on average, representing a substantial saving for the utility and its customers, including low-income customers. We identify options that offer strong synergies between economic and equity objectives for both types of adaptation option. The proposed framework is established to support the business case for climate adaptation in the water supply sector and to prioritise across flood and drought mitigation options. We take a first step towards mainstreaming equity considerations in water supply sector optioneering frameworks by estimating the contribution of adaptation options towards reducing household costs for low-income customers.